| Kilmona Fairdown Limited | Extraterritorial | 2016 |
| Kilmona Group Limited | Professional & scientific | 2016 |
| Kilmona Holdings Limited | Professional & scientific | 2005 |
| Kilmona Investments Limited | Professional & scientific | 2014 |
| Kilmona Private Equity Limited | Professional & scientific | 2005 |
| Kilmona Property Limited | Construction | 1994 |
| Kilmora Limited | Real estate | 2012 |
| Kilmore Properties Limited | Construction | 2020 |
| Kilmore Property Ltd | Other services | 2016 |
| Kilmore Service Station Limited | Wholesale & retail | 2016 |
| Kiln Court Apartments Management Limited | Households | 2008 |
| Kilrea Wind Ltd | Energy | 2016 |
| Kilronan Properties Limited | Administrative & support | 2006 |
| Kilsharan Limited | Information & communication | 2006 |
| Kiltagh Manor Ltd | Households | 2018 |
| Kilwarlin Estates Limited | Extraterritorial | 2002 |
| Kilwarlin Holdings Limited | Professional & scientific | 2016 |
| Kilwin Braid Family Investment Company | Financial services | 2026 |
| KIM Constable Limited | Arts & recreation | 2019 |
| KIM Johnston Executive Search Limited | Administrative & support | 2010 |
| KIM Mall Limited | Wholesale & retail | 2025 |
| Kimana (N.I.) Limited | Construction | 2013 |
| Kimm Trading Limited | Wholesale & retail | 2008 |
| Kimmers Port Management Limited | Extraterritorial | 1999 |
| Kimscourt Limited | Households | 1969 |
| Kinard Exports Limited | Wholesale & retail | 2019 |
| Kind Copy Limited | Administrative & support | 2021 |
| Kind Dog Ltd | Information & communication | 2025 |
| Kindercare Fostering Northern Ireland Limited | Health & social care | 2013 |
| Kinderguard Limited | Professional & scientific | 1997 |
| Kindmalov Ltd | Wholesale & retail | 2026 |
| Kindrum Consulting Ltd | Extraterritorial | 2018 |
| Kinelowen Grimley Ltd | Construction | 2023 |
| Kinetek Labs Limited | Information & communication | 2026 |
| Kinetek Ltd | Information & communication | 2023 |
| Kinetic Bards Studio Ltd | Information & communication | 2024 |
| Kinetic M&E Ltd | Manufacturing | 2020 |
| King and Fowler UK Limited | Manufacturing | 1980 |
| King Medical Ltd | Health & social care | 2009 |
| Kingarve Holdings Ltd | Real estate | 2022 |
| Kingarve Properties Limited | Real estate | 2024 |
| Kingarve Trading Limited | Extraterritorial | 2024 |
| Kings Hall Clinic Ltd | Health & social care | 2020 |
| Kingsbridge Apartments Management Company Limited | Professional & scientific | 2020 |
| Kingsbridge Foundation Limited | Health & social care | 2026 |
| Kingsbridge Healthcare Group Limited | Health & social care | 2015 |
| Kingsbridge Opticians & Hearing Clinic Limited | Health & social care | 2009 |
| Kingsbridge Private Hospital Belfast Limited | Health & social care | 2009 |
| Kingsbridge Private Hospital North West Limited | Health & social care | 1978 |
| Kingsbury Packaging (Limavady) Ltd | Extraterritorial | 2003 |
| Kingsbury Wagyu Ltd | Manufacturing | 2023 |
| Kingscourt (Balmoral) Limited | Extraterritorial | 1985 |
| Kingsford Capital Group Limited | Construction | 2026 |
| Kingsfort Square Management Limited | Households | 2008 |
| Kingsland Consultancy Limited | Wholesale & retail | 2021 |
| Kingsland Road Properties Limited | Real estate | 2023 |
| Kingsmill Wind Ltd | Energy | 2014 |
| Kingston Berkeley HMO Property Management Ltd | Households | 2021 |
| Kingston Berkeley Residential Property Management Ltd | Households | 2021 |
| Kingston Berkeley Sales & Rentals Ltd | Real estate | 2021 |
| Kingsway Court Management Company Ltd | Households | 2005 |
| Kingsway Drive Management Company Limited | Households | 2019 |
| Kingsway Park Management Company Ltd | Households | 2001 |
| Kinhateyu Ltd | Wholesale & retail | 2026 |
| Kiniot Ltd | Information & communication | 2025 |
| Kinky Limited | | 2007 |
| Kinlough & Coach House Management Company Limited | Administrative & support | 2008 |
| Kinnaird Mechanical Ltd | Manufacturing | 2023 |
| Kinnaird Terrace Property Management Ltd | Households | 2007 |
| Kinnear Electrical Limited | Wholesale & retail | 1977 |
| Kinora Limited | Professional & scientific | 2006 |
| Kinross Avenue Management Company Limited | Real estate | 2015 |
| Kinsetsu Limited | Information & communication | 2016 |
| Kinstar Limited | Financial services | 2025 |
| Kinstruct Developments Ltd | Construction | 2018 |
| Kintyre Heights Management Company Limited | Households | 2019 |
| Kinza Jamshad Ltd | Wholesale & retail | 2024 |
| Kion Restaurants Ltd | Hospitality | 2025 |
| Kipple Ltd | Information & communication | 2025 |
| Kirby East Limited | Other services | 2024 |
| Kirby Retail Limited | Wholesale & retail | 2011 |
| Kirill Igorevich Rakovki Ltd | Wholesale & retail | 2025 |
| Kirk Bryson & Co Limited | Real estate | 2013 |
| Kirk's Home Bakery Ltd | Manufacturing | 2014 |
| Kirker & Greer Whiskey Holdco Limited | Financial services | 2025 |
| Kirker & Greer Whiskey Limited | Extraterritorial | 2018 |
| Kirker Greer & Co Ltd | Financial services | 2022 |
| Kirker Greer (Holdings) Limited | Financial services | 2017 |
| Kirkham Recruitment Ltd | Manufacturing | 2016 |
| Kirkland Systems Limited | Real estate | 1989 |
| Kirklington Developments Ltd | Construction | 2023 |
| Kirkliston Property Ltd | Real estate | 2024 |
| Kirtan International LLP | | 2023 |
| KIT Bash Studio Ltd | Information & communication | 2018 |
| Kitchen Concepts (NI) Limited | Manufacturing | 2010 |
| Kitchen Design Consultancy Ltd | Professional & scientific | 2020 |
| Kitchen Design House Ltd | Manufacturing | 2020 |
| Kitchen Revamp Co Ltd | Other services | 2023 |
| Kitchenmaster (Holdings) Limited | Administrative & support | 2006 |
| Kitchenmaster Chemicals Group Limited | Administrative & support | 2026 |